public class Test {
     public  void main (String [] args ){
        System.out.println("Hello");
      //  声明一个变量
        int a;
      //   初始化
      a=10;
      //a=10.0编译时错误
      // 输出A到控制台
      System.out.println("a=" +a);

       //字符类型
        char c1 = 'a';
        char c2 = 'b';
        char c3 = 'c';
        char c4 = '你';
        char c5 = '好';
        System.out.println("c1:"+c1);
        System.out.println("c2:"+c2);
        System.out.println("c3:"+c3);
        System.out.println("c4:"+c4);
        System.out.println("c5:"+c5);
        System.out.println(System.getenv("JAVA_HOME"));

    
     }
    
}
